yes the plant must be mature enough to grow flowers befor it can be flowered trying to flower to early will result in your babies stretching due to the long periods of darkness

remember if you want small plants that the plants will continue to grow while flowering

and you should not lose potancy flowering small plants you just get less bud

i think if you want small plants that you can start flowering when ther small maybe try some clones there read to flower as soom as they root and tend to grow bushy and shorter than seedlings

good luck-smokes